Lithuania was the last European country to be Christianized
(1387). The Lithuanian state had been created as a defence against the
German crusaders who conquered the Baltic during the 13th century.
The constant wars transformed Lithuania into a great power and it controlled
a vast territory stretching from the Baltic sea to the Black sea. The reason why the Lithuanians became Christians 1387 was that their grand prince had
become king over Poland. Lithuania and Poland would thereafter often be in a
personal union, which 1569 was transformed into a real union. The Poles
dominated this union however and the Lithuanian nobility were gradually polonaised.